This is still a very doughy idea but I thought I would put it out there for ideas anyway. worst case scenerio is no body responds. Well here goes
I am a homebrewer and love to brew beer, however, as much as possible I would like to step lightly on the earth and brewing has some seriously questionable environmental effects. I try to buy only organic ingredients and I buy as local as I can. These two goals can sometimes interfere with each other but that is another story.
"So where's the stove question?" you may be asking.
Here it is
The BIGGEST worry I have is that I use propane to do the actual brewing. this involves heating around 15 gallons of water to around 180f and then maintaining a temp of around 150f for 1-2 hours and finally boiling around 13 gallons of liquid (now very full of sugar) for 1-2 hours.
I am also considering working a solarwater heater into the equation.
The maintaining step I accomplish with a big ol' beverage cooler but the initial heating and boiling is all propane on a big outdoor gas burner. So I was on here reading about RMH and I started to wonder if it would work for my purposes.
Two or three separate heaters, one for heating the water, one (or possibly a cooler area on the first) for maintaining temps (thus less plastic in my setup) and a third (or second) for doing the actual boil.
The additional idea I had was to creat this structure on three levels so that after water is put in the top I can move from one station to the next via gravity alone.
So other than the fact that this starts to look like a 15' long masonry behemoth does anyone have ideas? Critisisms (except of my spelling, no spell check on this computer). laudits and praise also gladly accepted.
I am a beer brewing rocketeer (just did a batch on tuesday) and can relate to your quest. I made a 1/2 barrel keg rocket wood stove conversion that works well as a hot liquor tank or brew kettle. But for real hot h20 making you need more surface area than just the bottom of a keg "barrel". So I built a tube shell heat exchanger but it is a bit of work,$, and more complicated. I added copper pipes in my mass bench so that I can extract hot h20 low tech for brewing or otherwise , or add hot h20 from my solar flat plate collectors to add heat to the mass. I think the pipes in a bench are a good low tech heat exchanger for lower temp heat (preheat) of brewing liquor. Rocket kettles are tall so must be built sturdy and stable even more so if you are going for a full three tier gravity system. Are you a welder? I think a bell with large enough copper pipes embedded in the top would be a sweet way to go for hot h20. Anyway, lots of ways to do it, just depends on your particular needs and $ and skills and time! My best advice, get rid of the plastic mash tun right away!